Control devices for dampers and the like

ABSTRACT

A control device is provided for dampers and the like which are adapted to be installed in a duct system whereby the combined control device and damper function as an air valve to control the flow of heated or cooled air to zones of individual rooms or offices of a building. The control device is mounted on a damper unit so as to be operatively engaged with a push rod which is utilized for simultaneously moving all of the blades of the damper unit from the closed to the open position thereof, with the blades being moved from their open to their closed positions preferably by means of a return spring. The control device includes a housing having a shaft extending outwardly from one end thereof and having any one of a plurality of interchangeable control caps detachably mounted at the other end of the housing in such a manner as to be operatively connected to the shaft. Each of the control caps is capable of housing therewithin the components of one of a plurality of different forms of electrical circuits, each of which is adapted to be actuated in response to a signal received from a thermostat. The outwardly extending shaft is operatively connected to one end of a worm gear which comprises one of the components of a gear train that is driven by an electrical motor, the latter being connected in circuit relation with the circuitry of the control cap and the thermostat. The other end of the gear train has mounted thereon a cam which is supported so as to be engageable with a cam follower that is connected to the push rod thereby providing the means whereby the control device is operatively engaged with the push rod of the damper unit to control the flow of air through a duct system, by controlling the extent to which the blades of the damper unit are opened or closed.

United: States Patent [1 1 Bauchmann m1 3,825,182 [451 July23, 1974 [54] CONTROL DEVICES FOR DAMPERS AND THE LIKE [76] Inventor: Donald K. Bauchmann, 1801 St. George Pl., Kinston, NC. 28501 22 Filed: May 17,1973 21 Appl. No.: 361,280

' [52] U.S. Cl. 236/1 C, 236/49, 236/78,

, 251/133, 310/6813 [51] Int. Cl 02k 11/00, F16k 31/04 [58] Field of Search 236/49, 1 C, l B, 78;

[56], References Cited UNITED STATES PATENTS 11/1967 Maynard...

2/1972 Romanelli Primary Examiner-William E. Wayner i push rod which is utilized for simultaneously moving all of the blades of the damper unit from the closed to the open position thereof, with the blades being moved from their open to their closed positions preferably by means of a return spring. The control device includes a housing having a shaft extending outwardly from one end thereof and having any one of a plurality of interchangeable control caps detachably mounted at the other end of the housing in such a manner as to be operatively connected to the shaft. Each of the control caps is capable of housing therewithin the components of one of a plurality of different forms of electrical circuits, each of which is adapted to be actuated in response to a signal received from a thermostat. The outwardly extending shaft is operatively connected to one end of a worm gear which comprises one of the components of a gear train that is driven by anelectrical motor, the latter being connected in circuit relation with the circuitry of the control cap and the thermostat. The other end of the gear train has mounted thereon a cam which is supported so as to be engageable with a cam follower that is connected to the push rod thereby providing the means whereby the control device is operatively engaged with the push rod of the damper unit to control the flow of air through a duct system, by controlling the extent to which the blades of the damper unit are opened or closed.

16 Claims, 12 Drawing Figures PATENIEDJUL23I9Y4 mm W 4 3,825,182

FIG. 12

1 FOR DAMPERS AND THE BACKGROUND OF THE INVENTION It has long been known in the prior art to employ dampers for purposes of regulating the flow of air through a heating or cooling duct system. Moreover, it has also been known heretofore to provide automatic means for opening and closing the damper to regulate the flow of air passing thereby as well as to perform this control function through the use of manual means. Dampers so equipped with control means, in effect, constitute air valves which are operable to control the amount of air flowing past a particular location in a duct system, thereby enabling uniform heating or cooling to be provided throughout a building through the ent portions of the duct system.

Based on past experience, it has been found that there are a number of characteristic features which it is desirable that such an air valve possess. For instance, an air valve should be capable of being utilized in both new as well as old duct systems. Particularly with regard to previously installed duct systems, it is desirable that the air valve be such as to permit easy installation thereof within such an existing duct system; In addition, the control device of the air valve should be operable to provide positive control over the movement of the damper. For this purpose, it has been found most desirable to position the control device so that it is capable of directly mechanically engaging the operating means of the damper unit.

From the standpoint of manufacturing and assembly considerations, there are a number of other desirable features which an air valve should possess. In this connection, it is desirable that the air valve embody a construction whichenables economies to be achieved in manufacture while yet providing for simplicity of assembly. It is, of course, obvious that some of the installations in which it is desired to utilize an air valve will require the use thereinof an air valve having a different mode of operation as compared to some other installation. This need to provide flexibility insofar as concerns the modes of operation with an air valve is capable of providing has commonly been accomplished by providing control devices which embody different types of control circuits. Heretofore, however, in order to change the electrical circuitry of the control device, it has been necessary to remove the entire control device and replace it with a different one. In addition to the time and expense involved in making this substitution there also exists the obvious possibility of improperly operatively connecting the new control device to the operating means of the damper unit. Moreover, providing a numberof different types of control devices increases the'cost of manufacture of the air valve because it minimizes the extent to which there exists commonal-- ity of parts, and also increases the costs of the parts distributors by requiring them to maintain a stock of all of these different types of control devices. Although a va riety of different forms of air valves have been provided as seen by reference to the prior art, they have all generally been found to be lacking with regard to one or more of the features referred to hereinabove.

Accordingly, it is an object of the present invention to provide a control device for'dampers and the like regulation of the amount of air flowing through differwhich is operable to control the operation of a damper unit thereby to control the flow of heated or cooled air in a duct system whereby to provide uniform heating or cooling throughout a building.

It is another object of the present invention to provide such a control device for dampers and the like which is mountable directly on the damper unit wherebydirect mechanical engagement exists between the control device and the operating means of the damper unit thereby ensuring that the control device exercises positive control over the operation of the damper unit.

A further object of the present invention is to provide such a control device for dampers and the like which includes a control cap embodying the electrical circuitry therefor that is interchangeable whereby to make it unnecessary to provide a completely different control device for each different type of control operation.

A still further object of the present invention is to provide such a control device for dampers and the like which through the selection of different control caps for embodiment therein is capable of providing either two position control, modulation control, or variable volume control.

Yet another object of the present invention is to provide such a control devicefor dampers and the like which is simple to assemble, provides economies of. manufacture by virtue of the provision for commonality of parts, and is capable of providing relatively long operating life and trouble-free operation.

SUMMARY OF THE INVENTION It has been found that the foregoing and related objects can be readily attained in a control device which is particularly adapted for controlling the operation of dampers and the like whereby to provide an air valve that is capable of being utilized to regulate the flow of air through a heating or cooling duct system to provide .uniform heating or cooling throughout a building. The control device includes an interchangeable control cap which isdetachably mounted on a housing whereby to be operatively connected to a shaft which is supported for rotation within the housing. The control cap embodies therein the components of an electrical control circuit which is actuated by a thermostat or controller. One end of the shaft extends outwardly of the housing and is connected to a worm gear so as to be driven therefrom. The worm gear constitutes one of the operating components of a gear train which is mechanically connected to the drive shaft of an electrical motor so as to be capable of being driven therefrom. The motor is connected electrically in circuit with the control circuitry embodied in the control cap and with the thermostat. The gear train has a cam supported at the other end thereof which is rotatable therewith. The cam operatively engages a cam follower which is in contact with the operating means of the damper unit whereby the cam functions to actuate the operating means through the cam follower. 1

In accordance with the preferred embodiment of the invention, three interchangeable control caps are adapted to be mounted on the housing. Each of these control caps embodies different control circuitry whereby to provide three different modes of operation, i.e., three different types of control, namely a two position control, a modulation control, and a variable vol- 3 ume control. The control cap and housing along with the motor and gear train driven thereby comprise the driver for the damper unit. The components of the gear train are supported within a gear box, the dimensions of which correspond to the housing whereby the gear box and the housing are capable of being assembled together to form a unit. The latter unit is mounted on one leg of a L-shaped mounting bracket with the motor being mounted on the other leg of the bracket. The L- shaped bracket in turn is supported on a driver mounting plate which is mountable directly on the damper unit in such a manner that the cam supported at one end of the gear train directly engages the cam follower which is in contact with one end of a push rod, which comprises one of the components of the operating means of the damper unit. The push rod is mechanic ally connected to the blades of the damper unit whereby through actuation of the push rod the blades are capable of being all simultaneously moved from a closed to an open position thereby controlling the flow of air past the damper unit. The blades are preferably returned to their closed position by means of a return spring.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 comprises a perspective view of an air valve consisting of a damper unit and a control device for controlling the operation of the damper unit, constructed in accordance with the present invention;

FIG. 2 is a side elevational view of a portion of the air valve of FIG. l'illustrated on an enlarged scale and depicting the manner in which the control device is operatively connected to the operating means of the damper unit in accordance with the present invention;

FIG. 3 is an exploded perspective view of a control device for dampers and the like constructed in accordance with the present invention;

FIG. 4 is aplan view partially in section of the gear box of a control device for dampers and the like constructed in accordance with the present invention, illustrated in association with a control cap and a cam, the latter components being depicted in exploded relation relative to the gear box;

FIG. 5 is a side elevational view of the gear train portion of a control device for dampers and the like constructed in accordance with the present invention;

FIG. 6 is a schematic circuit diagram of the control circuitry employed in a control device for dampers and the like constructed in accordance with the present invention for purposes of enabling the control device to provide variable volume control;

FIG. 7 isa schematic circuit diagram of the control circuitry employed in a control device for dampers and the like constructed in accordance with the present invention for purposes of enabling the control device to provide two step, i.e., position control and also illustrating the circuitry required for driving two such control devices from a single thermostat;

FIG. 8 is a schematic circuit diagram of the control circuitry employed in a control device for dampers and the like constructed in accordance with the present inventionfor purposes of enabling the control device to provide modulation control;

FIG. 9 is an exploded view partially in section of another form of terminal means which may be employed for purposes of externally making electrical connections to a control device for dampers and the like constructed in accordance with the present invention;

FIG. 10 is a partial sectional view of the alternative form of terminal means shown in FIG. 9, illustrated in assembled condition;

FIG. 11 is a side elevational view partially in section of one form of printed circuit board assembly employable in a control device constructed in accordance with the present invention; and

FIG. 12 is a side elevational view partially in section of another form of printed circuit board assembly employable in a control device constructed in accordance with the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT Referring now to the drawings and more particularly FIG. 1 thereof, there is illustrated therein an air valve, generally designated by reference numeral 10, which is comprised of a damper unit 12 and a control device 14 constructed in accordance with the present invention and operable for controlling the damper unit 12. The air valve 10 is particularly adapted to be installed in heating or cooling duct systems (not shown) wherein the air valve 10 functions to control the flow of heated or cooled air therethrough thereby regulating the amount of heating or cooling accomplished thereby. The air valve 10 is capable of being mounted in a suitable opening which has been cut for this purpose either through the side wall or through the bottom wall of a duct (not shown) of either a new or a previously existing duct system.

As most clearly understood with reference to FIGS. 1 and 2 of the drawings, the damper unit 12 consists of a substantially rectangularly shaped frame structure 16 which is formed by a pair of longitudinally extending side members 18 and 20, a bottom member 22 extending transversely between the side members 18 and 20 whereby to interconnect the latter members at one end thereof, and a mounting plate 24 provided at the other end of each of the side members 18 and 20 for a purposewhich will be described subsequently. A plurality of vanes 26 are supported between the side members 18 and 20 whereby to be capable of movement between open and closed positions relative to each other. Preferably, the vanes 26 consist of a plurality of individual blades which are suitably arranged relative to each other in such a manner as to provide a damper of the opposed-blade type.

For purposes of accomplishing the desired movement of the blades 26, each of these blades has a plurality of rod-like portions 28, 30 and 32 provided therein so as to extend the entire length thereof with one of the portions, i.e., portion 28 being located approximately at the center of the blade 26 and with the other two portions, i.e., portions 30 and 32 being located adjacent the edge of each of the long sides of the blade 26. As most clearly seen in FIG. 1 of the drawings, one end 28a of each of the rod-like portions 28 projects outwardly from the blade 26 a sufficient distance to enable the ends 28a of the portions 28 to be received within a plurality of openings (not shown) provided for this purpose in spaced relation along the length of the side member 20. Each of the latter openings (not shown) is suitably dimensioned so as to permit movement of the end 28a of the portion 28 therewithin. The outer end 28b of each of the elements 28 also projects outwardly of the blade 26 to a sufficient extent whereby to be capable of passing through anelongated slot 34 provided for this purpose in a slide member 36 and is received in one of a series of openings (not shown) provided therefor in the side member 18 similar to the manner in which the other ends 28a of the portions 28 are received in the aforedescribed openings provided in the side member 20. As such, the end 2812 is capable of movement within the slot 34 asthe slide member 36 is moved to cause the blades 26 to move between their open and closed positions aswill be described more fully hereinafter. One end 30a of each of the rodli-ke portions 30 also extends outwardly of the corresponding blade 26 so as to be capable of being received in one of a second series of slots 38 also provided in the slide member 36 in spaced relation to the aforementioned first series of slots 34 through which the ends 28b pass. The slide member 36 is suitablysupported in juxtaposed relation to the inner surface of the side member 18 whereby to be capable of sliding movement relative thereto. As the slide member 36 moves in a downwardly direction as viewed with reference to FIG. 1 of the drawings, the ends 30a of the portions 30 are forced downwardly through the engagement therewith with the ends of the slots 38 in which the ends 30a are received. This downward movement of the ends 30a of the portions 30 acts to cause the blades 26 to pivot about the ends 28a and 28b of the portions 28 thereby causing the blades 26 to move from the closed to the open position thereof. Theportion 28 therefore comprises the pivotal axis aboutv which the blade 26 pivots in moving between its open and closed positions. As the slide member 36 moves upwardly as viewed with reference to FIG. 1 of the drawings, the ends 30a of the portions 30 are also made -to move upwardly by virtue of their engagement with the ends of the slots 38 thereby causing the blades 26 to pivot about the ends 28a and 28b in moving from their open to their closed positions.

In accordance with the construction of the damper unit 12 shown in the drawings, downward movement is imparted to the slide member 36 through a push rod 40. As shown in FIG. 2 of the drawings, the push rod 40 is provided at its lower end with a notch 40a in which the upper end of the slide member 36 is received whereby to operatively connect the push rod 40 to the slide member 36. The push rod 40 extends through a plurality of openings provided for this purpose in the mounting plate 24, a driver mounting plate 42 to which further reference will be had subsequently, and preferably a flanged bearing 44 which functions as a support and guide means for the push rod 40 as the latter moves relative thereto. The push rod 40 is of suitable length so that the upper end 40b thereof extends upwardly a sufficient distance whereby to engage a cam follower means 46 which comprises the operating means whereby movement is imparted to the push rod 40 and therethrough to the slide member 36 to move the blades 26 from a closed to an open position.

For purposes of moving the blades 26 from their open to their closed position, a return spring 48 is preferably utilized. The latter spring 48 is connected to one end through a rod 50 to the mounting plate 24 while the other end of spring 48 is connected through a small plate-like member 52 to the slide member 36. The plate-like member 52is secured to the slide member 36 so as to be movable therewith and so as to project outwardly therefrom. The slide member 36 is biased upwardly by the spring 48 whereby when a downward force is no longer being applied through the cam follower means 46 to the push rod 40 and therethrough to the slide member 36, the upperbiasing force applied to the slide member 36 by the spring 48 is of sufficient strength to cause the slide member 36 to return to the position thereof illustrated in FIG. 1 of the drawings thereby causing the blades 26 to occupy their closed position as depicted therein.

Turning now to a consideration of the driver portion 54 of the air valve 10 by means of which the damper unit 12 is driven thereby to control the opening and the closing of the blades 26, the driver portion 54 as depicted in FIG. 3 of the drawings includes the control device 14, and the electrical motor 56 and a L-shaped mounting bracket 58 on which both the control device 14 and the electrical motor 56 are supported. Referring further to FIG. 3 of the drawings, the control device 14 as illustrated therein includes a control cap 60,.a housing 62, a gear box 64 and a cam 66. The control cap 60 consists of a housing cover 68 and a printed circuit board'70. The housing cover 68 is generally circular in shape and has a diameter the dimension of which is selected so as to enable the cover 68 to be inserted with a frictional fit into the top of the housing 62. In addition, the cover 68 is provided with a downwardly extending flange 68a integrally formed therewith around its circumference. The length of the flange 68a is less than the length of the distance measured between the top of the housing 62 and the shoulder 62a formed therewithin-whereby when the printed circuit board is inserted into the housing 62 so as to be seated on the shoulder 62a and the cover 68 is then inserted into the top of the housing 62, the printed circuit board 70 is captured between the shoulder 62a and the flange 68a of the cover 68, and the top of cover 68 is flush with the top surface of the side walls of the housing 62. For

purposes of ensuring that the proper alignment axists between the cover 68,the printed circuit board 70 and the housing 62 when the latter are all assembled together, the housing 62 is preferably provided along the inside of its side wall with a key 72. The cover 68 and the printed circuit board 70 are provided with a slot 68b, and 70a, respectively, which are dimensioned so as to be capable of receiving the key 72 therewithin with a sliding fit when the printed circuit board 70 and the cover 68 are assembled in the top of the housing 62.

Regarding printed circuit board 70, the latter as shown in FIG. 3 is generally circular in shape and has a diameter which is slightly less than the internal diameter of the housing 62 whereby to enable the printed circuit board 70 to be inserted therewithin. In accord with conventional practice, a plurality of electrical components (not visible in the drawings) are supported on one side of the printed circuit board 70 and the electrical interconnections therebetween are made on the other side of the printed circuit board 70 in the manner depicted in FIG. 3 of the drawings wherein a plurality of electrical leads 74 are visible. A plurality of terminals 76, each comprising a socket type eyelet suitably retained in an opening provided therefor, are provided in spaced relation around the circumference of the printed circuit board 70 whereby to enable electrical connections to be made therethrough to the electrical circuit components supported on the printed circuit board 70. The cover 68, which preferably is formed for a suitable non-conductive material, is provided with a series of openings 78 which are arranged around the circumference of the cover 68 in the same manner as the terminals 76 are arranged on the printed circuit board 70 whereby when the cover 68 and the printed circuit board 70 are assembled in the top of the housing 62, the openings 78 and the terminals 76 are aligned thereby to permit the end of a wire (not shown) to be inserted, when required, through one of the openings 78 into engagement with the terminal 76 aligned therewith thereby to complete an electrical connection between the latter terminal 76 and the wire. The cover 68 is provided with a hollow interior whereby to allow for clearance of shaft 80 as well as the other electrical components which are mounted on the upper surface of printed circuit board 70 when the latter is mounted in the housing 62 as above described.

Referring further to the construction of the printed circuit board 70, as shown in FIGS. 3, 11 and 12 of the drawings the board 70 is provided at its center with an opening suitably dimensioned in order to permit a shaft 80 to be mounted therewithin. In accord with the embodiment of the invention illustrated in FIG. 11 of the drawings, the shaft 80 which is formed of a nonconductivematerial is positioned in a bushing 82 which in turn is inserted into the aforedescribed ,central opening formed in the printed circuit board 70. In addition, the shaft 80 passes through the rotor 81a of the rotary switch 81, which in turn has its stator 81b soldered to the printed circuit board 70. t

For purposes of maintaining feedback control to which reference will be had more fully hereinafter, a

potentiometer 85 is employed mounted in spaced relation to the rotary switch 81 as illustrated in FIG. 12 of the drawings. The potentiometer 85 comprises a resistive element which is arrayed radially from its center and is supported on a phenolic wafer 87 having open eyelets. The wafer 87 is provided at its center with an opening suitably dimensioned so as to be capable of receiving therein the upper portion of bushing 82 as viewed with reference to FIG. 12 whereby to mount the wafer 87 on bushing 82. As shown in FIG. 12, a potentiometer wiper 89 is affixed to the uppermost portion of shaft 80. The potentiometer 85 is connected electrically to printed circuit board 70 by means of a plurality of elongated rivets 91, one end of which is received in the eyelets which are used to secure the aforereferenced resistive element on wafer 87. Shaft 80 with the wiper 89 positioned thereon is received in bushing 82 and the rotor 81a of rotary switch 81, and is retained in position by means of O-ring 83.

Now insofar as concerns the construction of the housing 62, the latter as shown in FIG. 3 of the drawings has a generally tubular configuration with the top thereof being open to enable the control cap 60 and printed circuit board 70 to bereceived therein as above described, and with the portion 62b having a lesser diameter than the top portion whereby to enable the bottom portion 62b to be inserted into the open end of the gear box 64 as will be referred to more fully hereinafter. Apart from the inwardly extending shoulder 62a described previously, the interior of the housing 62 is hollow for purposes of enabling the control cap 60, the printed circuit board 70 as well as some of the components mounted in the gear box 64 to be accommodated therein.

As will be more clearly understood with reference to FIGS. 3, 4 and 5 of the drawings, the gear box 64 houses a gear train 84. For this purpose, the gear box 64 which has a generally circular shape is constructed with the bottom wall 86 thereof being spaced inwardly from the bottom end of the gear box 64 as viewed with reference to FIG. 4 of the drawings. Extending outwardly from the bottom wall 86 towards the bottom end of the gear box 64, there are provided three tubular portions 88, 90 and 92, preferably formed as an integral part of the gear box 64, and arranged so that two of the portions, i.e., portions 90 and 92 are spaced equidistant from and on either side of the third portion, i.e., portion 88. The latter portion 88 is positioned approximately at the center of the bottom wall 86 and is provided with a hollow interior, the diameter of which is somewhat larger than the diameter of the hollow interior of the other two portions 90 and 92, the diameters of the hollow interiors of the latter two portions being substantially the same. The internal diameter of the portion 88 is dimensioned such as to permit one end of a shaft 94 to be received with clearance therebetween and for rotation relative thereto, and with a portion of the latter shaft 94 extending outwardly therefrom as most clearly shown in FIG. 4 of the drawings. The internal diameters of the other two portions, i.e., portions 90 and 92 are dimensioned so as to enable a pair of threaded openings (not shown) suitably embodied for this purpose in the gear train 84 thereby to provide a means for mounting the gear train 84 within the gear box 64 and so as to be positioned against the bottom wall 86 thereof. For a purpose which will be described hereinafter, each of the fasteners 96 preferably is provided with an enlarged head 96a and with a portion of the shaft 96b thereof having a greater diameter than the threaded portion of the shaft but having a lesser diameter than the enlarged head 96a thereof.

Referring again to FIGS. 3, 4 and 5 of the drawings, the gear train 84 as illustrated therein includes a substantially U-shaped spring clip 98 which is fastened by means of suitable fasteners such as a pair of rivets 100 to an upper gear bracket 102, the latter being provided with a pair of openings (not shown) suitably formed therein for purposes of receiving the rivets 100. Preferably the spring clip 98 is provided with a pair of outwardly extending flanges 980 which are sufficiently resilient that when the housing 62 is inserted into the top of the gear box 64 as viewed with reference to FIG. 4 of the drawings, the portion 62b of the housing 62 engages the flanges 98a causing the latter to deflect inwardly and thereby apply a biasing force against the inner surface of portion 62b which serves to hold the housing 62 positioned within the gear box 64. In addition, it has been found that with this construction when an attempt is made to remove the housing 62 from the gear box 64, the flanges 98a tend to dig into the inner side wall of the portion 62b thereby resisting the outward movement of the housing 62 relative to the gear box 64. In this connection, it is, of course, to be understood that for this purpose the housing 62 is preferably made from some non-metallic material.

As best understood with reference to FIGS. 4 and 5 of the drawings, the upper gear bracket 102 is substantially U-shaped in configuration having a pair of downwardly extending leg portions with flanges extending outwardly at the ends thereof. The upper gear bracket 102 is fastened by suitable means such as a pair of rivbe set forth hereinafter.

Preferably both of the legs of each of the upper and lower gear brackets 102 and 104 have a semi-circular cutout (not shown) formed in each of the legs thereof whereby when the gear brackets 102 and 104 are assembled together the aforesaid semi-circular cutouts define a pair of circular openings (not shown). A worm gear shaft bearing 110 of the worm shaft means 106 is positioned in each of the aforementioned circular openings. A worm shaft valve control member 112 is supported in the bearings 110 soas to be rotatable relative thereto. The ends of the member 112 project outwardly of the bearings 1 and one end of the member 112 is provided with a notch 112a for a purpose which will be referred to hereinafter. Intermediate the bearings 110, there is mounted a worm gear 114 on the member 112; The worm gear 114 is suitably retained on the member 112 so as to be rotatable therewith. Although not visible in the drawings, preferably a washer is interposed between each of the bearings 110 and the ends of the worm gear114.

With further reference to FIGS. 4 and 5 of the drawings, the main gear shaft means 108 includes a pair of main shaft gear bearings 116. One of the bearings 116 is received inan opening (not shown) suitably provided in the upper and lower gear brackets 102 and 104 whereby when the latter brackets 102 and 104 are assembled together as previously described, the aforementioned openings are aligned whereby to enable the main gear shaft 94 to be received within the bearings 116 with the opposite ends of the shaft 94 projecting outwardly therefrom. The shaft 94 has a helical gear 118 supported thereon for rotation therewith. In addition, the helical gear 118 is suitably positioned on the gear shaft 94 intermediate the bearings 116 whereby y when the main gear shaft means 108 is assembled within the upper and lower gear brackets 102 and 104 in the manner depicted in FIG. 4 of the drawings, the helical gear 118 is operatively engaged with the worm gear 114 of the worm shaft means 106. In accord with the illustrated embodiment of the invention, a shakeproof washer 120 is preferably provided on the shaft 94 between one of the bearings 116 and a shoulder 94a, the latter being integrally formed as a part of the shaft 94. One end 94b of the shaft 94 is notched as shown in FIG. 4 of the drawings whereby to permit the end 80a of the shaft 80 to be inserted therein thereby to operatively lock the shafts 94 and 80 together whereby the latter two shafts will move together. The cam 66 which has an opening 120 formed at the center thereof is mountedon the other end, i.e., end 94c of the shaft 94, the latter end 94c being received within the opening 120. For purposes of mounting the cam 66 on the shaft 94, the end 94c of the latter is preferably knurled as shown in FIG. 4 so as to ensure the establishment of a secure inner connection between the cam 66 and the shaft 94.

Continuing with a description of the components which constitute the driver portion 54 of the air valve 10, the control device 14 is fastened to-one leg 58a of the substantially L-shaped bracket 58 by means of the aforedescribed pair of shoulder screws 96. The latter screws 96 perform the dual functions of fastening the gear train 84 in the gearbox 64 and of fastening the control device 14 to'the bracket 58. The leg 58a of bracket 58 is provided with three openings (not shown) which are suitably spaced relative to each other so as to correspond to the spacing between and thereby be 'alignable with the three portions 88, and 92 formed as a part of the gear box 64. The screws 96 are received in the outer two of these three openings and the shaft 94 extends through the third, i.e., the center one of these three openings. More particularly, a bushing 122 having a reduced shoulder portion is preferably supported in the latter, i.e., the third of the three openings with the reduced shoulder portion of the bushing 122 being positioned within the opening, and the end 940 of the shaft 94passes through the bushing 122before being received in the opening in the cam 66. In accord with the illustrated embodiment of the invention, a strap spring 124 is supported in juxtaposed relation to the bushing 122 so as to be positioned with the ends of the spring 124 bearing against the outer surface of the bottom wall 86 of the gear box 64 and with the center portion of the spring 124 bearing against the bushing 122 which has the effect of biasing the bushing 122 outwardly, i.e., up against the leg 58a of the bracket 58.

The motor 56 is mounted on the other leg, i.e., other leg 58b of the L-shaped bracket 58. For this purpose, the leg 58b is provided with a pair of openings 126 which are suitably spaced relative to each other. In addition, the leg 58b has formed therein an opening 128, the diameter of the latter opening 128 is dimensioned such as to permit the shaft 130 of the motor 56 to pass therethrough and to be received in the notched end 112a of the member 112 whereby to lock the shaft 130 and member 112 together in operative engagement. Suitable openings (not shown) are provided in the housing 56a of the motor 56 through which pass a pair of threaded fasteners 132 that are threadily engaged in the openings 126 whereby to secure the motor 56 to the leg 58b of the bracket 58 and to lock the shaft 130 to the member 112. The motor 56 comprises a conventional 24V., 6OHZ electrical motor.

Referring now to FIGS. 1 and 2 of the drawings, as illustrated therein the driver portion 54 is mounted on the damper unit 12, and more particularly on the mounting plate 24 thereof by means of a driver mounting plate 134. The latter plate 134 includes a pair of leg portions 134a and 134b which intersect substantially at right angles to each other whereby to provide the plate 134 with a generally L-shaped configuration. The leg portion 134a of the plate 134 is provided with an elongated slot 136 which is formed therein so as to extend inwardly from one edge thereof. In addition, the leg 134a is provided with an opening (not shown) suitably dimensioned to receive a fastener 138 therein. In order to mount the driver portion 54 on the mounting plate 134, the driver portion 54 is oriented relative to the leg portion 134a so that the shoulder screws 96 are aligned relative to the elongated slot 136. The driver portion 54 is then slid relative to the leg portion 134a so that the shoulder screws 96 and the shaft 94 are received in the slot 136 whereby the enlarged heads 96a of the screws 96 are positioned on one side of the leg portion 134a along with the cam 66 and the L-shaped mounting bracket 58 is positioned on the other side of the leg portion 1340. With the shoulder screws 96 and the shaft 94 positioned in the slot 136, the fastener 138 which is received in the aforedescribed opening (not shown) in the leg portion 134a is threaded into the threaded opening 140 provided therefor in the mounting bracket 58. If so desired, the driver portion 54 could also be mounted to the leg portion 134a by enlarging the slot 136 whereby the latter would be dimensioned so as to be capable of receiving the bushing 122 with a sliding fit.

With the driver portion 54 so mounted on the leg portion 134a of the driver mounting plate 134, the latter plate 134 is mounted on the mounting plate 24. For this purpose, the leg portion 134b of driver mounting plate 134 is positioned in juxtaposed relation to the mounting plate 24. The plate 134 is fastened to the plate 24 by means of suitable fastening means such as a pair of rivets (not shown) which are received in spaced openings (not shown) provided for this prupose in the leg portion 134b and the plate 24, the latter openings being positioned in leg portion 13412 and plate 24 whereby to be alignable relative to each other.

As shown in FIG. 2 of the drawings, a cam follower means 46 is supported on the leg porton 134a whereby to be positioned thereon so as to be engageable by the cam 66 when the driver portion 54 is mounted on the leg portion 134a in the manner described above. The cam follower means 46 comprises a triangular-shaped cam follower 142 which is mounted by means of a fulcrum stud 144 on the leg portion 134a so as to be capable of pivoting relative thereto. The latter fulcrum stud 144 passes through an opening (not shown) provided for this purpose in one corner of the cam follower 142 and is received in an opening (not shown) provided thereforin leg portion l34aof the driver mounting plate 134. A wheel 146 is mounted for rotation on a stud 148 which is supported in an opening (not shown) provided in one of the other two corners of the cam followers 142 whereby to be engageable by the cam 66. Another wheel 150 is mounted for rotation on a stud 152 which is supported in an opening (not shown) provided for this purpose in the other corner of the cam follower 142 whereby to be capable of engaging the hexagonal push rod 40 when the driver mounting plate 134 is fastened on the mounting plate 24.

Turning now to a consideration of FIGS. 6, 7 and 8 of the drawings, there are illustrated therein schematic circuit diagrams of the different types of control circuitry that are capable of being embodied in a control cap 60 and which is operable when embodied therein to provide the air valve with different modes of operation.

Referring first to FIG. 7 of the drawings, there is shown therein the schematic circuit diagram for the control circuitry 154 which is operable to provide the air valve 10 with two-step control. The lattertype of control which is the least refined form of control with which the air valve 10, in accordance with the illus-- trated form of the invention, is designed to be provided is operable to causethe air valve 10 to function in either thefully open or fully closed position. With reference to FIG. 7, theportion of the circuitry 154 embodied within the dotted line enclosure 156 comprises the circuitry for operating the driver portion 54 and the circuitry embodied within the dotted line enclosuRc 158 comprises the circuitry for the single pole, double throw snap acting type thermostat whereby the temperature of an area is sensed. For purposes of exemplifying the fact that one thermostat may be utilized for operating two driver portions 54, there is illustrated in the dotted line enclosure 160 in FIG. 7 the circuitry for operating a second driver portion 54.

Referring again to FIG. 7 of the drawings, power is supplied to the circuitry 154 from a suitable 24 volt source through terminals 162 and 164. The terminal 162 is connected by lead 166 in circuit with one side of the unidirectional motor 56. The other side of the motor 56 is connected by lead 168 to a switch means 170. The switch means 170 includes a pair of switch terminals 170a and 17%. Switch terminal 170a is connected by lead 172 to switch terminal 174a of switch means 174. Similarly, switch terminal 170!) is connected by lead 176 to switch terminal l74b. Switch means 174 is connected by lead 176 to the other input terminal 164 and by the lead 178 to terminal 180. Terminals 180 and 182 are utilized for connecting the circuitry 154 in circuit with the controls of either a furnace or an air-conditioner (not shown). Terminal 182 is connected to switch terminal 184a of switch means 184 by lead 186. The latter switch means 184 is connected in common with switch means 174 and switch means 188.

In accord with the control circuitry depicted in FIG. 7 of the drawings, that portion thereof which is embodied in enclosure 156 comprises the circuitry of the master drive portion 54 and that portion which is embodied in the enclosure 160 comprises the circuitry for a slave drive portion. With reference to FIG. 7, it can be seen therefrom that lead connects one side of the motor 192 of the slave drive unit with the input terminal 162. The other side of the motor 192 is connected by lead 194 to switch means 196. Switch means 196 is connected in common with switch means 198 and switch means 200. In addition, switch terminals 196a and 1961; of switch means 196 are connected by leads 202 and 204 to switch terminals 188a and 188b, respectively, of the aforedescribed switch means 188.

The circuitry as schematically represented in FIG. 7 depicts the positions occupied by the various switch contacts when the driver portion 54 has driven the air valve '10 to a closed, i.e., satisfied position and the room thermostat is satisfied for a heating installation. As the room cools, the thermostat contact will switch from terminal 170a to 170b providing a flow of current through the motor 56. During the demand cycle, contact is established between the switch contact of switch means 184 and switch terminal 184a and therethrough to terminal 182. This activates the heating controls of a furnace if the-terminals 180 and 182 are connected to a furnace as in the illustration being described or the cooling controls of an air-conditioner if the terminals 180 and 182 are connected to an airconditioner. At the end of the pre-established time period, the contact of switch means 174 transfers from switch terminal 174b to switch terminal 174a. The self interrupting contacts of the drive portion 54 stop the motor 56. The air valve 10 is now open. When the thermostat becomes satisfied with the driver portion 54 in the aforedescribed demand position, the thermostat contact, i.e., the contact of switch means 170 shifts back to switch terminal 170a from terminal 170b, thereby again providing a flow of current to the motor 56. After a pre-established time period, the driver portion closes and all of the switch contacts return to their original positions, i.e., the positions depicted in FIG. 7, and motor circuit is automatically broken by switch means 174. In accord .with the mode of operation of the two-step control circuitry 154, once driver portion 54 has been energized, the air valve '10 must run from one of its extreme positions to the other, i.e., through 90 movement of the cam 66 and remain there until conditions at the thermostat or control have changed through the entire range of its differential. It is also noted that when the air valve is in its demand position, a normally open end switch connected in circuit with the terminals 180 and 182 closes. If two driver portions are controlled by a single thermostat as schematically represented in FIG. 7, th motor switch assembly of the driver portion included in the dotted line enclosure 156, i.e., the motor switch assembly to which the thermostat is connected becomes the master and the remaining driver portion,'i.e., that depicted in dotted line enclosure 160 operates as the slave or follower. It should be noted that in systems having master driver and follower portions, the master driver portion will respond to control changes first and the follower driver portion will then change its position relative to the master driver portion. However, by reversing the wires 202 and 204, the master drive portion will be made to open, and the slave drive portion made to close.

A vernier adjustment is provided which is operable for purposes of adjusting the amount of air which bypasses the air valve 10. The Vernier adjustment consists of scribe lines 206 which asdepicted in FIG. 1 of the drawings have been stamped on the gear box 64 and the housing 62 in which the control cap 60 is inserted. The scribe lines 206 have been provided for balancing oversize and undersize duct work at the installation site. Aligning the housing 62 to the black scribe line on the gear box 64 will allow normal operation of the valve 10, i.e., full opening and full closing of the valve 10 will occur. By offsetting these black scribe lines, an equal offset willoccur at the valve blades 26 relative to the duct (not shown). A maximum offset should not exceed 40, i.e., the position of the red scribe line on the gear box 64. In accord with the preferred form of the invention, two-position, variable volume and modulation control caps can be adjusted in the aforedescribed manner.

Referring next to FIG. 6 of the drawings, there is shown therein the schematic circuit diagram for the control circuitry 208 which is operable to provide the air valve 10 with a variable volume control. The latter type of control refers to the mode of operation wherein a reversing drive mechanism is utilized to provide a degree of modulation. In accordance therewith, if the area being heated or cooled is sensed to reach the desired temperature before the vanes or blades 26 reach their fully'open position, the drive portion 54 compensates by reversing the blades 26. As illustrated in FIG. 6, the control circuitry 208 includes a thermostat override control2l0, a floating thermostat preferably a single pole, double throw thermostat having a neutral center position and comprising that portion of the control circuitry 208 which is embodied within the dotted line enclosure 212, and the circuitry for the valve driver 14 V portion 54 which is the circuitry found enclosed within the dotted line enclosure 214. Power is supplied to the control circuitry 208 from a suitable 24 volt source through the terminals 216 and 218. Terminal 216 is connected by lead 220 to switch means 222, the latter including the switch terminal 222a and a switch terminal 222b. Switch terminal 222a is connected by lead 224 to switch means 226, the latter as shown in FIG. 6 being in contact with switch terminal 226a. Switch means 226 also includes a switch terminal 226!) which corresponds to an open operating position. Switch terminal 226bis connected by lead 228 to switch means 230. The latter switch means 230 includes a pair of switch terminals 230a and 23017, the former beingconnected in circuit by lead 232 with switch terminal 226b and also to one side of a reversible motor 234. The other switch terminal, i.e., switch terminal 230b is connected in circuit with switch terminal 2260 and another side of the reversible motor 234 by lead 236. Finally it will be noted that input terminal 218 is connected to the motor 234 by lead 238. The terminals 240 and 242 are provided for purposes of connecting the control circuitry 208 in circuit with the controls of either a furnace or an air-conditioner (not shown) whereby to control the operation of the latter when the control circuitry 208 is not in the completely satisfied condition.

With regard to the mode of operation of the control circuitry 208, once the circuitry 214 of the driver portion 54 is energized, the air valve 10 and more particularlythe blades 26 of the damper unit 12 can move from one of the extreme positions to the other as the cam 66 moves through This movement takes place at a relatively low speed, i.e., approximately seconds for full travel. Components will remain in this relative position until conditions at the thermostat or controller have changed. Limit switches A and B open on either end of the 90 travel to open the coils of motor 234 so as to prevent over travel. If the floating thermostat or controller changes direction before full travel is achieved, the driver portion 54 and more particularly the motor 234 will reverse and cause the blades 26 to be driven in the opposite direction. This process of reversing direction at the command of the thermostat or controller gives a control similar to proportional control without the need for a balancing relay or a null amplifier controlled by a proportional thermostat. With this form of control, the air valve 10 can be at rest at any position within the 90 range of travel. By virtue of the nature of the floating thermostat, when the thermostat is satisfied, switch means 230 will be in a neutral position, i.e., will not be making contact with either contact 230a or 230b. Only when the thermostat calls for more or less air will the contact 230a or the contact 230b be in its closed circuit condition, and thereby allow movement of the valve 10. At any discrete position of travel, when the thermostat is satisfied, the motor'234 will be deenergized.

Although external switches 222 and 226 have been included in the control circuitry 208 shown in FIG. 6 of the drawings in the interest of completeness of description, in accord with the recommended method of control utilizing the circuitry shown in FIG. 6, external switches 222 and 226 are preferably eliminated and wire 220 is connected directly to the common of thermostat 230,the other switches being ancillary in nature. Although not shown it is to be noted that it is possible if desired to operate units in parallel.

Thus, it can be seen that with variable volume control, once the driver portion 54 is energized, the air valve will run only enough to vary the supply of air in the duct to satisfy the thermostat or controller 212. If the thermostat 212 were replaced by a single pole, double throw snap acting type thermostat a different mode of operation would take place. In accordance therewith, when the thermostat or controller 212 changes direction before full travel is achieved, the driver portion 54 and more particularly the motor 234 will reverse and cause the blades 26 to be driven to their opposite extreme position. The air valve 10 would then always be driven openor closed and would never be at rest unless it were driven to one of its extreme positions, i.e., full open or full close if the thermostat 212 remained in the position that commanded this for a period of time. Only during this period would the valve 10 be at rest. An integral normally open switch (not shown) connected in circuit with the terminals 240 and 242 is closed when the air valve 10 is in any position other than fully closed.

Referring now to FIG. 8 of the drawings, there is shown therein a form of control circuitry 244 which is capable of being embodied in a control cap 60 for purposes of providing the air valve 10 with modulation control. This form of control functions to anticipate heating or cooling requirements of a zone or room, and through electronic control means regulates the blades 26 of the damper unit 12 by degrees. The control circuitry 244 as shown in FIG. 8 of the drawings includes a portion which is enclosed within the dotted line enclosure 246 and which comprises the circuitry for a proportional thermostat controller, a portion which is enclosed within the dotted line enclosure 248 and which for purposes of describing the mode of operation ofthe control circuitry 244 has been depicted as comprising an electro-mechanical balancing relay although in accord with one form of the invention a solid state null amplifier which performs the same function as the electromechanical balancing relay is employed in place thereof, either of them however, can be used, and finally includes a portion which is illustrated enclosed in the dotted line enclosure 250 and which comprises the circuitry for the driver portion 54. Referring more particularly to FIG. 8 of the drawings, power is supplied from 24 volt source through leads 252 and 254 to a pair of input terminals 256 and 258. Input terminal 256 is connected by lead 260 to one side of reversible motor 262 and by lead 264 to a potentiometer 266, the latter being divided into a portion 266a to the left of the lead 264 as viewed with reference to FIG. 8 of the drawings and a portion 266b to the right of the lead 264. The portion 266a of potentiometer 266 is connected by lead 268 to a first relay coil 270 and to one side 272a of a second potentiometer 272. Similarly, the other portion, i.e., side 266b of potentiometer 266 is connected in circuit by lead 274 to a second relay coil 276 and the other side, i.e., side 272b of the second potentiometer 272. Input terminal 258 is connected in circuit with a single pole, double throw switch means 278. Switch contact 278a of switch means 278 is movable between contact with a first switch terminal 278b which is connected by lead 280 to the motor 262 and contact with a second switch terminal 278c which is connected by lead 282 to the motor 262. In accordance formed by the potentiometers 266 and 272 is balanced,

i.e., the resistance of the portions 272b and 266a of the potentiometers 272 and 266 equals the resistance of the portions 272a and 266b thereof. Resistance in the proportional thermostat controller potentiometer 272 being balanced with the resistance in the motor potentiometer 266 no current flows through either coil 270 or 276. Now if the temperature sensed by the controller 246 rises, the wiper 272c of potentiometer 272 moves to the left reducing the resistance between the left end of the potentiometer 272 as viewed with reference to FIG. 8 of the drawings and the wiper 272e, i.e., the resistance of portion 272a of the potentiometer 272 decreases. The current flow through the left end of the controller 246 as viewed with reference to FIG. 8 is increased, and the increased current in relay coil 270 pulls in the switch means 278, i.e., causes the switch contact 278a to move into contact with switch terminal 278b. Current then flows through the switch means 27 8 to the counterclockwise coil, i.e., coil 262a of motor 262. The motor 262 runs counterclockwise to reposition the aforementioned bridge circuit. As the motor 262 runs, it moves the wiper 266c of motor potentiometer 266 towards the right as viewed with reference to FIG. 8 of the drawings. Whenthe wiper 2660 on the motor potentiometer reaches the point where the resistance between the wiper 2660 and the right end of the motor potentiometer 266 equals the resistance between the wiper 272c and the left end of the controller potentiometer 272, i.e., the resistance of portions 272b and 266a of potentiometers 272 and 266 equals the resistance of the portions 272a and 266b thereof, current in relay coils 270 and 276 ceases. This opens the relay contacts, stopping the motor 262 and the circuitry 244 is again in balance. The mode of operation of modulating control circuitry 244 is such that it can not control a heating or cooling plant as there are no terminals included therein capable of being utilized for purposes of connecting an end switch therewith. As such, the control to shut down or start such equipment must come from another source. As depicted in FIG. 8 the circuitry 244 whereby modulating control is provided to an air valve 10 consists of a modulating driver portion 250, a balancing relay 248 or null amplifier 248 and a proportional thermostat controller 246. Units can be ganged together, off of one common thermostat, i.e., it is possible to use a common proportional thermostat controller with ganged potentiometers, and two modulating driver portions with their associated null amplifiers. The method of operation of the control circuitry 244 when a temperature increase occurs has been described hereinabove, however, it is understood that when the temperature decreases, the current flows through relay coil 276 and the motor 262 is caused to run in the opposite direction, i.e., clockwise, the coil 262b of motor 262 comprising a clockwise coil.

Thus, with modulation control, once the driver portion 54 is energized, the air valve 10 will run only enough to vary the duct supply in direct ratio to the amount of change at the proportional thermostat controller 246, i.e., for a discrete amount of thermostat movement the air valve 10 and more particularly the blades 26 of the damper unit 12 will open or close a discrete amount. However, the cam 66 is capable of full travel through thereby to cause the blades 26 to move between their fully open and their fully closed positions. Limit switches C and D open on either end I of the 90 travel of the cam 66 to open the coils of portion 54. In accordance therewith, the printed circuit 7 'board 70 is provided with a plurality of openings 284 which are similar in nature to the openings 76 described previouslyhereinabove, but which are dimensioned so as to be capable of receiving therein the tip 286a of a tapped bushing 286. The latter bushing 286 is received in an opening 288 provided for this purpose in the non-conductive control cap 60. As illustrated in FIG. 10, the bushing 286 is received with a sliding fit in the opening 288 with the top 286a being received in an opening 284 in the printed circuitboard 70. The tip 286a is preferably soldered to the printed circuit board 70. Also, in accord with the preferred form thereof, the bushing 286 is provided with a knurled portion 286b which is operable to prevent pullout and turning when the bushing 286 has been inserted in the opening 288. In its outer surface the control cap 60 is provided with a countersunk hole 290 which is dimensioned so that the diameter thereof exceeds the diameter of a terminal screw 292 which is intended to be threaded into the bushing 286. In addition, a radially extending slot 294 is formed in the upper surface of the control cap 60 having one end thereof which begins at the outer circumference of the control cap 60 and the other end which terminates beyond the hole 290. The slot 294 is dimensioned such that a wire (not shown) is capable of being inserted therethrough to a position wherein one end of the wire overlies the top of the bushing 286. Withthe wire so located, the screw 292 is tightened so as to capture the wire between the bushing 286, the screw 292 and the wall of slot 294 thereby to establish a good electrical connection therebetween.

A description of the mode of operation of the air valve 10 and more particularly a description of the manner in which the damper unit 12 is controlled by the driver portion 54 will now be provided. As described hereinabove, the driver portion 54 is mounted on the mounting plate 24 so that the cam 66 is engageable with the cam follower means 46 and so that the latter means 46 is also operatively connected to the push rod 40. The control circuitry embodied in the driver portion 54 which controls the operation of the push rod 40 and thereby the blades 26 by controlling the rotation of the cam 66 is itself responsive to signals imparted thereto from a suitable thermostat or controller which is connected in electrical circuit relationship with the driver portion 54. Thus, when the thermostat or controller senses that a deviation exists in the temperature desired to be present in a certain location, the thermostat or controller operates to transmit an electrical signal indicating this fact to the control circuitry of the driver portion 54. Depending on the particular form, of control circuitry which is embodied in the driver portion 54, i.e., whether there is present the circuitry to provide two-step control, or variable volume control, or modulation control, the blades 26 will .be caused to'move in accordance with one of these methods of operation. More particularly, the control circuitry will cause the motor 56 of the driver portion 54 18 r I to rotate in a prescribed fashion which rotation in turn is imparted to the cam 66. As most clearly illustrated in FIG. 2 of the drawings, the cam 66 is provided with a profile for unidirectional or bi-directional rotation as dictated by the control cap used, whereby as the cam rotates through 90, full travel of the push rod 40 will take place. More specifically, with the cam 66 positioned as shown in solid lines, the push rod 40 is at its uppermost position, and the blades 26 are in their fully closed position. With the cam 66 rotated 90 to the dotted line position thereof depicted in FIG. 2, the push rod 40 is at its lowermost position, and the blades 26 occupy their fully open position. This opening and 010s ing of the blades 26 is utilized for purposes of controlling the flow of heated or cooled air in a duct system thereby to provide a means whereby a particular room or zone thereof is capable of being maintained at a desired temperature.

Although several embodiments of control devices constructed in accordance with thepresent invention have been shown in the drawings and described hereinabove, it is nevertheless to be understood that'other modifications in the construction thereof may still'be made thereto by those skilled in the art without departing from the essence of the invention. In this connection, some'of the modifications which can be made in the subject control device have been alluded to hereinabove, while others will become readily apparentto those skilled in the art when exposed to the present description and illustration of the construction of a control device for dampers and the like. For example, the control cap 60, housing 62 and gear box 64 could be configured so as to be provided with an otherthan circular shape, without departing from the essence of the invention. In addition, the circuitry capable of being embodied in the driver portion 54 could take other forms whereby to provide the air valve '10 with other different modes of operation without departing from the essence of the invention.

Thus, it can be seen that the present invention provides a novel and improved control device for dampers and the like which is operable to control the operation of a damper unit thereby to control the flow of heated or cooled air in a duct system whereby to provide uniform heating or cooling throughout a building. Moreover, the control device for dampers and the like of the present invention is readily adapted to be utilized in new or existing heating and cooling systems. Furthermore, in accord with the present invention, a control device for dampers and the like has been provided which is mountable directly on the damper unit whereby direct mechanical engagement exists between the control device and the operating means of the damper unit thereby ensuring that the control device exercises positive control over the operation of the damper unit. The control device for dampers and the like of the present invention includes a control cap that embodies the electrical circuitry thereof and which is interchangeable whereby to make it unnecessary to provide a completely different control device for each different control operation. In addition, in accord with the present invention there is provided a control device for dampers and the like which-through the selection of different control caps for embodiment therein is capable of providing either two position, i.e., step control, variable volume control or modulation control. Finally, the control device for dampers and the like in accord with the present invention is simple to assemble, provides economies of manufacture by virtue of the provision for commonality of parts, and is capable of providing relatively long life and trouble-free operation.

Having thus described the invention, I claim:

1. In an air valve for a heating or cooling duct system including a damper unit having blade means supported therein for movement between first and second positions for regulating the amount of air flowing through the duct system, the improvement of a control device for controlling the movement of the blade means of the damper unit, said control device comprising:

a. an interchangeable control cap means having a first shaft supported therein for rotation relative thereto and with one end of said first shaft projecting outwardly therefrom, and also having supported therein the electrical circuitry for one control circuit selected from a plurality of different types of control circuits;

b. electrical circuit means connecting said one control circuit in electrical circuit relationship with the thermostat wherein said one control circuit operates in response to electrical signals received from the thermostat;

gear means including a gear box for. detachably mounting said interchangeable control cap means thereon and gear train means supported with said gear box including a second shaft having one end thereof operatively connected to said one end of said first shaft and the other end thereof having operating means mounted thereon, said gear train means further including drive means operatively connected to said second shaft for driving said second shaft and thereby also said first shaft whenever said drive means is being driven;

d. motor means electrically connected in circuit relation with said one control circuit for receiving control signals therefrom and operatively connected to said drive means of said gear train means whereby said motor means drives said drive means in response to the control signals received by said motor means from said one control circuit; and

e. mounting means for mounting said control device on the damper unit with said operating means operatively connected with the blade means supported in the damper unitwhereby when said second shaft is driven by said drive means in response to the control signals received by said motor means from said one control circuit, said operating means causes the blade means to move between the first and second positions thereof.

2. In an air valve, the improvement of a control device as set forth in claim 1 wherein said interchangeable control cap means comprises a housing detachably mounted. in said gear box, a printed circuit board mounted in said housing and having said first shaft mounted thereto and the electrical circuitry of said one control circuit supported thereon, and a control cap detachably supported on said housing and operable to retain said printed circuit board mounted in said housing, said control cap including means provided therein for making electrical connection therethrough to said printed circuit board.

3. In an air valve, the improvement of a control device as set forth in claim 2 wherein said printed circuit board includes a plurality of terminals formed therein, and said means provided on said control cap for making electrical connections therethrough to said printed circuit board comprises a plurality of wire-receiving openings.

4. In an air valve, the improvement of a control device as set forth in claim 2 wherein said means provided in said control cap for making electrical connections therethrough to said printed circuit board comprises a plurality of tapped bushings each positioned in an opening provided therefor in said control cap and having one end thereof electrically connected to said printed circuit board, a plurality of wire-receiving slots formed in said control cap whereby each of said plurality of wire-receiving slots communicates with one of said openings, and a terminal screw threaded into each of said plurality of tapped bushings and operable to electrically connect a wire positioned in one of said plurality of wire-receiving slots with one of said plurality of tapped bushings.

5. In an air valve, the improvement of a control device as set forth in claim 1 wherein a helical gear is mounted on said second shaft intermediate the ends thereof for rotation therewith, and said drive means includes a third shaft having one end thereof operatively connected to said motor means and having a worm gear supported thereon intermediate the end thereof for rotation therewith, said worm gear being operatively connected to said helical gear for transmitting drive therethrough from said motor means to said second shaft.

6. In an air valve, the improvement of a control device as set forth in claim 5 wherein said motor means includes an electrical motor having a drive shaft operatively connected to said one end of said third shaft.

7. In an air valve, the improvement of a control device as set forth in claim 1 wherein said plurality of different types of control circuits includes a two-step control circuit, a variable volume control circuit and a modulation control circuit.

8. In an air valve, the improvement of a control device as set forth in claim 1 further comprising a mounting bracket having first and second leg portions intersecting substantially at right angles to each other, said interchangeable control cap means and said gear means being supported on said first leg portion and said motor means being supported on said second leg portion.

9. A control device operable to perform a control function comprising:

a. an interchangeable control cap means including a housing having a first motion transmitting means projecting outwardly therefrom, support means positioned in said housing and supporting thereon the electrical circuitry for one control circuit selected from a plurality of different types of control circuits, said one control circuit being operable in response to electrical signals received from an external source connected in electrical circuit relationship therewith, and a control cap detachably supported in said housing and operable to retain said support means positioned in said housing;

b. gear means including a gear box for detachably mounting said interchangeable control cap means thereon, and gear train means supported within said gear box including a second motion transmitting means having one end thereof operatively connected to said first motion transmitting means and having an operating means mounted on the other end thereof, said gear train means further including drive means operatively connected to said second motion transmitting means and thereby said first motion transmitting means whenever said drive means is being driven;

c. motor means electrically connected in circuit relation with said one control circuit for receiving control signals therefrom and operatively connected to said drive means of said gear train means whereby said motor means drives said drive means in response to the control signals said motor means receives from said one control circuit; and

d. a mounting bracket including a pair of leg portions, one of said pair of leg portions having said interchangeable control cap means and said gear means supported thereon and the other of said pair of leg portions having said motor means supported thereon whereby when said second motion transmitting means is driven by said drive means in response to the control signals received by said motor means from said one control circuit said operating means is operable to perform a control function. i

10. A control device as set forth in claim 9 wherein said first motion transmitting means comprises a first shaft, said second motion transmitting means comprises a second shaft, said second shaft having a helical gear supported thereon intermediate the ends thereof for rotation therewith, and said drive means includes a third shaft having one end thereof operatively connected to said motor means and having a worm gear supported thereon intermediate the ends thereof for rotation therewith, said worm gear being operatively connected to said helical gear for transmitting drive therethrough from said motor means to said second shaft.

11. A control device as set forth in claim 9 further comprising vernier adjustment means operable for adjusting the control device to the operating parameters of a particular control function application, said vernier adjustment means including means mounting said housing for rotation relative to said gear box means whereby the control device is adjusted by rotating said housing relative to said gear box thereby to offset said housing relative to said gear box and indicia comprising scribe lines provided on said housing and said gear box in juxtaposed relation relative to each other and operable for visually depicting the extent to which said housing is offset relative to said gear box.

12. A control device as set forth in claim 9 wherein said motor means includes an electrical motor having a drive shaft operatively connected to said drive means and said motor is detachably supported on said other of said pair of leg portions of said mounting bracket.

13. A control device as set forth in claim 9 wherein said operating means comprises a cam and a cam follower operatively connected to each other whereby rotational movement of said cam is translated into linear movement of said cam follower.

14. A control device as set forth in claim 13 wherein said cam follower is detachably connected to a controlled device and said cam follower imparts a linear force to the controlled device for purposes of performing a control function relative thereto.

15. A control device as set forth in claim 13 wherein said cam has a configuration enabling said cam to actuate said cam follower when the mode of movement of said cam is unidirectional as well as when the mode of movement of said cam is bidirectional.

16. A control device as set forth in claim 9 further comprising mounting means for detachably mounting said interchangeable control cap means and said gear means as an assembled unit on said one of said pair of leg portions of said mounting bracket. 

1. In an air valve for a heating or cooling duct system including a damper unit having blade means supported therein for movement between first and second positions for regulating the amount of air flowing through the duct system, the improvement of a control device for controlling the movement of the blade means of the damper unit, said control device comprising: a. an interchangeable control cap means having a first shaft supported therein for rotation relative thereto and with one end of said first shaft projecting outwardly therefrom, and also having supported therein the electrical circuitry for one control circuit selected from a plurality of different types of control circuits; b. electrical circuit means connecting said one control circuit in electrical circuit relationship with the thermostat wherein said one control circuit operates in response to electrical signals received from the thermostat; gear means including a gear box for detachably mounting said interchangeable control cap means thereon and gear train means supported with said gear box including a second shaft having one end thereof operatively connected to said one end of said first shaft and the other end thereof having operating means mounted thereon, said gear train means further including drive means operatively connected to said second shaft for driving said second shaft and thereby also said first shaft whenever said drive means is being driven; d. motor means electrically connected in circuit relation with said one control circuit for receiving control signals therEfrom and operatively connected to said drive means of said gear train means whereby said motor means drives said drive means in response to the control signals received by said motor means from said one control circuit; and e. mounting means for mounting said control device on the damper unit with said operating means operatively connected with the blade means supported in the damper unit whereby when said second shaft is driven by said drive means in response to the control signals received by said motor means from said one control circuit, said operating means causes the blade means to move between the first and second positions thereof.
 2. In an air valve, the improvement of a control device as set forth in claim 1 wherein said interchangeable control cap means comprises a housing detachably mounted in said gear box, a printed circuit board mounted in said housing and having said first shaft mounted thereto and the electrical circuitry of said one control circuit supported thereon, and a control cap detachably supported on said housing and operable to retain said printed circuit board mounted in said housing, said control cap including means provided therein for making electrical connection therethrough to said printed circuit board.
 3. In an air valve, the improvement of a control device as set forth in claim 2 wherein said printed circuit board includes a plurality of terminals formed therein, and said means provided on said control cap for making electrical connections therethrough to said printed circuit board comprises a plurality of wire-receiving openings.
 4. In an air valve, the improvement of a control device as set forth in claim 2 wherein said means provided in said control cap for making electrical connections therethrough to said printed circuit board comprises a plurality of tapped bushings each positioned in an opening provided therefor in said control cap and having one end thereof electrically connected to said printed circuit board, a plurality of wire-receiving slots formed in said control cap whereby each of said plurality of wire-receiving slots communicates with one of said openings, and a terminal screw threaded into each of said plurality of tapped bushings and operable to electrically connect a wire positioned in one of said plurality of wire-receiving slots with one of said plurality of tapped bushings.
 5. In an air valve, the improvement of a control device as set forth in claim 1 wherein a helical gear is mounted on said second shaft intermediate the ends thereof for rotation therewith, and said drive means includes a third shaft having one end thereof operatively connected to said motor means and having a worm gear supported thereon intermediate the end thereof for rotation therewith, said worm gear being operatively connected to said helical gear for transmitting drive therethrough from said motor means to said second shaft.
 6. In an air valve, the improvement of a control device as set forth in claim 5 wherein said motor means includes an electrical motor having a drive shaft operatively connected to said one end of said third shaft.
 7. In an air valve, the improvement of a control device as set forth in claim 1 wherein said plurality of different types of control circuits includes a two-step control circuit, a variable volume control circuit and a modulation control circuit.
 8. In an air valve, the improvement of a control device as set forth in claim 1 further comprising a mounting bracket having first and second leg portions intersecting substantially at right angles to each other, said interchangeable control cap means and said gear means being supported on said first leg portion and said motor means being supported on said second leg portion.
 9. A control device operable to perform a control function comprising: a. an interchangeable control cap means including a housing having a first motion transmitting means projecting outwardly therefrom, support means positioned in said housing and supportiNg thereon the electrical circuitry for one control circuit selected from a plurality of different types of control circuits, said one control circuit being operable in response to electrical signals received from an external source connected in electrical circuit relationship therewith, and a control cap detachably supported in said housing and operable to retain said support means positioned in said housing; b. gear means including a gear box for detachably mounting said interchangeable control cap means thereon, and gear train means supported within said gear box including a second motion transmitting means having one end thereof operatively connected to said first motion transmitting means and having an operating means mounted on the other end thereof, said gear train means further including drive means operatively connected to said second motion transmitting means and thereby said first motion transmitting means whenever said drive means is being driven; c. motor means electrically connected in circuit relation with said one control circuit for receiving control signals therefrom and operatively connected to said drive means of said gear train means whereby said motor means drives said drive means in response to the control signals said motor means receives from said one control circuit; and d. a mounting bracket including a pair of leg portions, one of said pair of leg portions having said interchangeable control cap means and said gear means supported thereon and the other of said pair of leg portions having said motor means supported thereon whereby when said second motion transmitting means is driven by said drive means in response to the control signals received by said motor means from said one control circuit said operating means is operable to perform a control function.
 10. A control device as set forth in claim 9 wherein said first motion transmitting means comprises a first shaft, said second motion transmitting means comprises a second shaft, said second shaft having a helical gear supported thereon intermediate the ends thereof for rotation therewith, and said drive means includes a third shaft having one end thereof operatively connected to said motor means and having a worm gear supported thereon intermediate the ends thereof for rotation therewith, said worm gear being operatively connected to said helical gear for transmitting drive therethrough from said motor means to said second shaft.
 11. A control device as set forth in claim 9 further comprising vernier adjustment means operable for adjusting the control device to the operating parameters of a particular control function application, said vernier adjustment means including means mounting said housing for rotation relative to said gear box means whereby the control device is adjusted by rotating said housing relative to said gear box thereby to offset said housing relative to said gear box and indicia comprising scribe lines provided on said housing and said gear box in juxtaposed relation relative to each other and operable for visually depicting the extent to which said housing is offset relative to said gear box.
 12. A control device as set forth in claim 9 wherein said motor means includes an electrical motor having a drive shaft operatively connected to said drive means and said motor is detachably supported on said other of said pair of leg portions of said mounting bracket.
 13. A control device as set forth in claim 9 wherein said operating means comprises a cam and a cam follower operatively connected to each other whereby rotational movement of said cam is translated into linear movement of said cam follower.
 14. A control device as set forth in claim 13 wherein said cam follower is detachably connected to a controlled device and said cam follower imparts a linear force to the controlled device for purposes of performing a control function relative thereto.
 15. A control device as set forth in claim 13 wherein said cam has a configuration enabling said cam to actuAte said cam follower when the mode of movement of said cam is unidirectional as well as when the mode of movement of said cam is bidirectional.
 16. A control device as set forth in claim 9 further comprising mounting means for detachably mounting said interchangeable control cap means and said gear means as an assembled unit on said one of said pair of leg portions of said mounting bracket. 